The Detached Binary TW Coronae Borealis

New radial velocity and photometric data for TW CrB have been obtained, and Roche-based simultaneous analysis of RV and light curve data for the system has been accomplished for the first time, using the 2003 version of the Wilson-Devinney code. Values for the masses and radii have been obtained: M₁ = 1.31 (6) M_ʘ, M₂ = 1.22 (4) M_ʘ, and R₁ = 1.50 (1) R_ʘ, R₂ = 1.42 (1) R_ʘ. For the luminosities the most likely values are L₁ = 2.78 (5) L_ʘ and L₂ = 2.01 (4) L_ʘ. Both stars are likely unevolved. There is general agreement with earlier photometric values for Zhang and Zhang (2003) with the exception of their masses and mass ratio. Because the values in this paper for the latter quantities are based on radial velocities, they are to be preferred.     

Eclipsing Binary Stars in Nearby Galaxies

We briefly discuss the survey programme we are conducting to detect eclipsing binaries in local group galaxies. Some lightcurves from studies of M31, IC 1613 and NGC 6822 are presented along with details of future work.     

The Eccentric Eclipsing Binary V889 Aquilae

Several new times of minimum light recorded with photoelectric or CCD means have been gathered for the eccentric eclipsing binary V889 Aql (P = 11.1 days, e = 0.37). Its O–C diagram is presented, and improved elements of the apsidal motion and the light-time effect (LITE) are given. We found a long apsidal motion period of about 24 400 ± 2400 years and a period of the third body of about 52 ± 2 years.     

Spot and Facula Activity Variations of the Eccentric Detached Eclipsing Binary KIC 8098300 Based on the Time-series Orbital Solutions

The LAMOST spectra and Kepler light curves are combined to investigate the detached eclipsing binary KIC 8098300,which shows the O'Connell effect caused by spot...     

The Eclipsing Binary bx Andromedae and its Orbital Period Behaviour

The orbital period variations of the eclipsing binary BX And are examined analysing its (O–C) diagram 1) with the standard method, in which the minima times are fitted by the quadratic ephemeris combined with an assumed light-time effect, and 2) with the first continuous method. The results from the use of the two methods are, as was expected, different.     

Detection of Pulsation and Additional Components in Eclipsing Binary RS Sct

The eclipsing binary star RS Sct is a semi-detached system of the β Lyrae type. This system was photometered for six nights in 2019 August, and 2020 June and August. The light and radial velocity curves were simultaneously analyzed to obtain the absolute physical and orbital parameters of the system, and the system geometry was determined. In this system, the primary component has filled its inner Roche lobe and the secondary component is close to filling it. Moreover, the change in the orbital ...     

Possible Light-Time Effect in the Eclipsing Binary System TY Boo

The O − C diagram for the eclipsing binary system TY Boo was constructed with the new minima times observed at the Ankara University Observatory along with the collected ones from the literature. The O − C diagram shows a cyclic variation superimposed on a quadratic variation. The quadratic variation can be explained in terms of mass loss/exchange mechanism in the system while the cyclic variation is attributed to a possible light-time effect caused by a third body revolving around the close binary.     

Third Body Problem in the Eclipsing Binary Star TV Cassiopeia

The aim of this work is to search for some evidences for the presence of unseen companion(s) in the eclipsing binary star TV Cassiopeia using its O—C diagram. Assuming that the light-time effect is responsible for the periodic components on the O—C diagram, the set of orbital parameters were derived using Irwin's (1959) method. The resulting orbital parameters and mass of the hypothetical third body are physically acceptable. Lacking other proofs of the third body presence, however, the hypothesis can be treated as a probable case only.This revised version was published online in October 2005 with corrections to the Cover Date.     

Six Newly Discovered Eclipsing Binary Systems in the TESS field

We present the first detailed investigation of six eclipsing binary systems in the TESS field. The TESS light curves of the targets are analyzed by determining the initial effective temperatures via SED fits. The absolute parameters are derived and the systems are compared to well-known binaries of the same type. Results show that CD-58791,CD-621257 and TYC 9356-355-1 are detached binary systems. CD-54942 and UCAC4 136-007295 are contact binaries while TYC 8508-1413-1 is a semidetached system.     

Bm Cas: A Long-Period Eclipsing Binary with A Supergiant and a Common Envelope

New results of UBVR photometry of the long-period eclipsing binary BM Cas obtained at Tallinn Observatory between 1979 and 1996 are discussed.     

The outermost ob associations in M33

The blink survey ofUBVR plates of the Tautenburg Schmidt telescope reveals about 20 new stellar associations. A few suspected associations are located at 8 kpc from the center of M33. The new associations fit well into the spiral structure of the galaxy.     

引力常数随时间变化对双星(密近食双星)轨道演变的影响(圆形轨道情形)

研究了引力常数随时间变化对食双星轨道演变的影响。理论结果表明:轨道半径和轨道周期以线性形式随时间缩减,但无周期变化、圆形轨道的形状只有周期和混合长期项(Poisson项)。对5颗密近食双星的轨道半径和轨道周期的长期演变的上下限做了数值估计,并具体讨论了理论结果和其他效应的对比。     

不相接双星的相互照射吸收和子星表面温度的变化

本文对不相接双星系统的子星间相互照射吸收进行了计算,从理论上得到子星的表面温度分布情况．对已知基本参数的３３个晚型双星系统中的反映子星等温面和等势面偏离程度的量进行了统计．结果表明,冷子星上等温面和等势面的偏离程度普遍较热子星的要大,该结果支持了Ｚｈｏｕ和Ｌｅｕｎｇ所提出的用气旋和反气旋来解释恒星黑子和太阳黑子巨大差别的可能性．本文还考虑了临边昏暗效应在晚型双星系统中对子星之间相互照射吸收的影响,这种影响达１８％以上．临边昏暗效应对热子星的影响普遍比冷子星要大．     

Apsidal Motion in Detached Binary Stars: Comparison of Theory and Observations

A list of 62 detached binaries having reliable data on the rotation of the line of apsides is considered. Theoretical estimates of the rate of apsidal motion are obtained. These estimates are compared with observational data. It is shown that cases in which the theoretical estimate exceeds the observed value are several times more frequent than cases in which the theoretical value is lower than the observed one. This discrepancy increases when systems with more reliable observational data are considered.     

Das geschwindigkeitsellipsoid derHII-regionen in M33

The peculiar radial velocities ofHii regions in M33 varies with position angle in a manner that can be explained by an ellipsoidal distribution with minor axis in the direction of rotation. The amplitude of the variations, however, is too great as compared with theory or experience in the galaxy.

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Mitteilungen Serie A, Nr. 36.     

Distance estimation of the LMC,SMC, and M33 from the apparent radius distribution ofHii-regions

The size distribution ofHii-regions in the LMC, SMC, and M33 is used to estimate their distances. The values deduced are: 42.66±2.51, 89.73±5.03, and 755.11±47.14 kpc, respectively.     

1SWASP J010313.78+352903.7: A Totally Eclipsing Binary with Components in Poor Thermal Contact

We presented photometry for an EB-type totally eclipsing binary, 1SWASP J010313.78+352903.7, observed with the Xinglong 85 cm telescope on 2021 October 22. Light curves in five bands(including the TESS data) were analyzed by employing the Wilson–Devinney method. The photometric solutions show that it is a contact binary with a relatively low mass ratio(q ≌ 0.28), relatively large fill-out factor( f ≌ 40%) and large temperature difference(Δ T ≌ 1700 K). Max.I-Max.II is up to about 9% of variable ...